A device of this nature is, for example, known from DE 20204085 U1. Here, the milk/air mixture is passed into the milk chamber where it is mixed with steam. Directly following the mixing chamber is a settling section consisting of a number of settling channels in parallel to the flow, each of which forms a discharge opening on an open end for the discharge of a milk foam flow to the outside. According to the associated EP 1344477 B1 the clearance diameter of the cross-section of each of these settling channels should be dimensioned in a ratio to its length which is 1 to at least 10 overall divided by the number of settling channels. Due to very long settling channels which are relatively small in cross-section, the steam/air/milk mixture flows as evenly as possible from the device and no splashes arise. The disadvantage is however that the channels are relatively small in cross-section, but relatively long, resulting in the requirement for continual cleaning. Otherwise the channels become very quickly blocked with clinging milk protein. Moreover, the relatively long settling section also leads to the forming of a relatively long foaming device.
Further measures for settling the steam/air/milk mixture discharged from the mixing chamber are described in EP 0858757 B1 and in EP 1115317 B1.